select issue_date from stamps,color_master,printsize_master,np_master where stamps.issue_date!=''  and np_master.np_code=stamps.np_code and np_master.np='P'  and printsize_master.printsize_code=stamps.printsize_code and printsize_master.printsize='4.4  x 3.6'  and color_master.color_code=stamps.color_code and color_master.color='Multicolour'   and issue_date!='' order by issue_date